Boris and Natasha from Rocky and Bullwinkle are the original examples, working under Fearless Leader.
Jackie Chan Adventures: The Dark Hand devolved into this from regular mooks over the course of the series. It eventually got to the point where Finn, Ratso, and Chow were actively trying to avoid crime in favor of having legitimate jobs, as they were tired of constantly getting roped into being the henchmen for each season's villain. In fact, they even play a key role in helping fight Drago in the Grand Finale.
The HIVE Five serve as this as well as an Evil Counterpart to the Teen Titans. This group originally consists of Jinx, Gizmo, and Mammoth with See-More being added later as well as Privite HIVE, Kyd Wyckyd, and Billy Numerous on separate occasions.
The second season of W.I.T.C.H. goes through a grand total of three of these, starting off with the Knights of Vengeance, then the Knights of Destruction, and finally CHKYN (it's their initials).
Transformers Cybertron also has the group of Decepticons who stay loyal to Galvatron; Thundercracker, Ransack, Crumplezone, and Thunderblast. However, during the final battle, when they realize Galvatron was never going to spare them either, they abandon him too. Thundercracker even ends up happily working with the Autobots on the Space Bridge Project after Galvatron's death, until the other three shanghai him into their 'New Decepticon Army'.
The Spectacular Spider-Man has the Enforcers fill this role for the Big Man, while the Sinister Six (sometimes the whole team, sometimes just one or two members) do the same for the Master Planner, aka Doc Ock. Interestingly, the Enforcers are shown to report to their organization's Dragon, Hammerhead, while Electro, the Planner's Dragon, is merely the most powerful and loyal of the Six.
Super Robot Monkey Team Hyperforce Go! features the Sun Riders. Granted, they are ex-actors (and therefore used to trying to impress crowds). And hey, at least they have the dignity to save their posing for after they win.
In the Codename: Kids Next DoorAn Asskicking Christmas, the Delightful Children From Down the Lane have the Faculty Four, who represent Substitute Teacher's Day to help their plot to Steal Christmas. Their members are Thesaurus Rex, a dinosaur made up of books, the Unintelligible Tutor, who's babbling incapacitates people, The Human Text, a flying humanoid made up of stacks of paper, and Mr. Fantastically Fit, a stretchy muscle man, led by Ms. Edna Ucation.
Interestingly, back when they were visualized as side characters of Mr. Warburton's failed Kenny and the Chimp, the Kids Next Door (or rather those Kids Next Door as they were called then) were intended to be examples of this trope◊.